Hoosiers, having been spoiled by this week's near-record warmth, will get a rude awakening beginning Friday, as the leading edge of a vast pool of chilly air pours over Indiana.
This chilly air promises to bring Indiana its lowest temperatures of the season thus far.
Temperatures Friday will hold up to 25 degrees below the balmy upper 70s and lower 80s reached on Thursday.
Put another way, highs will be in the lower to mid-50s in most of northern and central Indiana.
Indianapolis hit 78 degrees on Wednesday, and was expecting at least as high on Thursday. Friday's forecast was for a high of 54 degrees under rainy skies.
The agent for change, a cold front plowing into the Midwest from the Great Plains, will cross the Hoosier State with a band of rain and even thunderstorms Thursday night and early Friday.
Slowing of the front west of the state will allow rainy weather to linger in the afternoon in central and eastern Indiana.
Meanwhile, the coldest weather will not begin until early next week, when all but southernmost Indiana can look forward to highs in the 40s.
A cold front swinging into the Northeast will bring the threat of severe weather to part of the region on Tuesday afternoon.
The late-season swelter will continue along much of the Atlantic Seaboard through the week as tens of millions head back to school and work.
Tropical Storm Dolly has formed in the southwestern Gulf of Mexico's Bay of Campeche and will continue its west-northwest path during the next couple of days.
A second volcanic eruption occurred on Sunday morning in Iceland in the same area that had one on Friday.
While flooding is a threat, monsoonal rains will be beneficial for most areas across northwest India this week.
While Labor Day marks an unofficial end to the summer, the Chicago area will see warm, humid conditions continue before temperatures slide late in the week.
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